150km out of a tank seems a bit of a stretch eh
In saying that, I routinely get over 100kms out of my 9.5L. Have a mate with a 15 250R, running the same jetting over the same loops, at the same pace. A few times now he's chewed through an extra litre and had to borrow 1/2 a litre more to get back while I haven't even touched reserve. He's also running taller gearing (a tooth less on the rear).